getting "broken pipe" at about 1.2 MB files (from HP-UX to macOS) ... how fix?
Solution 1:
It looks like the remote end is killing the connection. My guess would be a timeout somewhere in the chain - it may be that there are SSHD settings to tweak on the osma host?
Otherwise, have you tried using rsync instead of scp? It supports resuming transfers so even if you had to run the command multiple times it would get there eventually.